The invention concerns a closure cap, in particular a closure cap for a container containing carbonated beverages.
A large number of different embodiments of screw closure caps made of plastics material are used today for the closing of containers, such as e.g. beverage bottles.
The final position, when the closure cap is in its fully screwed-on state, is determined on the one hand by the screwing-on, twisting moment and on the other hand, by the relationship between geometry of the closure cap and the container mouth. In particular, in the case of closure caps with internal lip seals, the final position of the closure cap is reached, when the inside of the cap top plate rests against the front side of the container mouth in the manner of a stop.
One problem with such known closure caps consists in so-called overturning. If a user mistakenly tries to twist a mounted closure in the wrong direction using force (i.e. continuing to screw-on instead of unscrewing) there is a danger that the threads of the closure cap may snap over the threads of the container mouth. Thus, the closure cap may temporarily become disengaged from the container mouth. In particular, in the case of bottles with contents held under pressure, such as carbonated beverages for example, there is a danger that at the same time, the closure may fly off the bottle i.e. missiling. Such missiling can injure the user.
Overturing safeguards have already been suggested, which prevent such overturning or in the event of overturning lead to a controlled gas blow-off. In WO95/21095 a braking element is described, which is arranged outside the thread path used to mount the closure and which, in the event of attempted overturning, engages with the thread of the container mouth. Overturning is thereby avoided.
This solution has the disadvantage that the closure cap is greatly deformed in the radial direction in the event of overturning.
Braking elements are also known, which define the end of the screwing-on process; thus from WO 90/10581 a braking element acting in the axial direction or in the circumferential direction is known, which towards the end of the screwing-on process engages with the start of the thread of the container mouth and so limits the screwing-on process.